1nbd_aio_trim(3) LIBNBD nbd_aio_trim(3)
2
3
4
6 nbd_aio_trim - send trim command to the NBD server
7
9 #include <libnbd.h>
10
11 typedef struct {
12 int (*callback) (void *user_data, int *error);
13 void *user_data;
14 void (*free) (void *user_data);
15 } nbd_completion_callback;
16
17 int64_t nbd_aio_trim (struct nbd_handle *h, uint64_t count,
18 uint64_t offset,
19 nbd_completion_callback completion_callback,
20 uint32_t flags);
21
23 Issue a trim command to the NBD server.
24
25 To check if the command completed, call nbd_aio_command_completed(3).
26 Or supply the optional "completion_callback" which will be invoked as
27 described in "Completion callbacks" in libnbd(3).
28
29 Other parameters behave as documented in nbd_trim(3).
30
31 By default, libnbd will reject attempts to use this function with
32 parameters that are likely to result in server failure, such as
33 requesting an unknown command flag. The nbd_set_strict_mode(3)
34 function can be used to alter which scenarios should await a server
35 reply rather than failing fast.
36
38 This call returns the 64 bit cookie of the command. The cookie is ≥ 1.
39 Cookies are unique (per libnbd handle, not globally).
40
42 On error "-1" is returned.
43
44 Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
45 of the error.
46
48 The handle must be connected with the server, otherwise this call will
49 return an error.
50
52 This function first appeared in libnbd 1.0.
53
54 If you need to test if this function is available at compile time check
55 if the following macro is defined:
56
57 #define LIBNBD_HAVE_NBD_AIO_TRIM 1
58
60 nbd_aio_command_completed(3), nbd_can_trim(3), nbd_create(3),
61 nbd_set_strict_mode(3), nbd_trim(3), "Issuing asynchronous commands" in
62 libnbd(3), libnbd(3).
63
65 Eric Blake
66
67 Richard W.M. Jones
68
70 Copyright (C) 2019-2021 Red Hat Inc.
71
73 This library is free software; you can redistribute it and/or modify it
74 under the terms of the GNU Lesser General Public License as published
75 by the Free Software Foundation; either version 2 of the License, or
76 (at your option) any later version.
77
78 This library is distributed in the hope that it will be useful, but
79 WITHOUT ANY WARRANTY; without even the implied warranty of
80 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
81 Lesser General Public License for more details.
82
83 You should have received a copy of the GNU Lesser General Public
84 License along with this library; if not, write to the Free Software
85 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
86 02110-1301 USA
87
88
89
90libnbd-1.7.12 2021-05-29 nbd_aio_trim(3)